Internal circuits of wireless communication devices are generally provided on printed circuit boards (PCBs). Such PCB technologies have been rapidly developed. Currently, there are generally used not only typical hard PCBs but also flexible PCBs (FPCBs) freely movable.
On the other hand, as a high frequency line used in wireless terminals such as mobile phones, particularly, a radio frequency (RF) line, generally a coaxial cable is used. However, since an internal space of a wireless terminal is small and various kinds of circuit modules are mounted thereon, it is not easy to form a communication line using the coaxial cable in such space.
Accordingly, it is necessary to provide a transmission line capable of effectively transmitting a high frequency signal without noise while doing no harm on other modules. With respect to this, a structure, in which a signal is transmitted inside a wireless terminal using an FPCB, has been provided.
However, in this case, signals are merely transmitted using the FPCB. There is not disclosed a structure capable of being simply assembled, being optimized for impedance matching, and minimizing a loss of signals.
Korean Patent No. 10-1153165 B1 describes a high frequency telecommunication line.